Answer: -
2.5 moles of calcium atoms are in 2.5 moles of calcium carbonate CaCO₃
Explanation: -
In order to solve such types of problems, the first step would be to write the chemical formula of the compound.
The chemical formula of calcium carbonate = CaCO₃
The chemical symbol of Calcium is Ca.
From the formula of calcium carbonate we can see that
1 mole of CaCO₃ has 1 mole of Ca
2.5 mole of CaCO₃ has 
= 2.5 mol of Ca.
∴2.5 moles of calcium atoms are in 2.5 moles of calcium carbonate CaCO₃
D it is only physical and not chemical
The name of CuO is Copper(II) oxide have the two most common oxidation states of copper are +2 and +1.
<h3>What is copper oxide used for?</h3>
Copper oxide is a trace element for the zootechnical and agricultural sector. Cupric oxide is also used as a raw material for the production of catalysts and pigments in the field of ceramics, glass and plastics.
This compound makes two different types of bonds being the hydrogen bond when it's a hydrogen and covalent bond when we have an oxygen or a nitrogen.
See more about Copper(II) oxide at brainly.com/question/24217869
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